1. Technical Field
The present invention relates to an electronic device, an electronic apparatus, a method of manufacturing a base substrate, and a method of manufacturing an electronic device.
2. Related Art
In the related art, electronic devices having an electronic component such as a piezoelectric element accommodated in a package have been known. Moreover, as the package, a configuration having abase substrate and a lid (lid portion) bonded together via a bonding member has been known (for example, refer to JP-A-2011-211681 (Patent Document 1)).
The electronic device disclosed in Patent Document 1 has a base substrate, a piezoelectric element fixed to the base substrate, and a lid bonded to the base substrate so as to cover the piezoelectric element. Moreover, an insulating layer and an insulating adhesive are present between the base substrate and the lid. With the insulating layer and the insulating adhesive, the lid is bonded to the base substrate.
Here, as a method of bonding the base substrate with the lid, a method has also been known, in addition to the method of using an insulating adhesive like in Patent Document 1, in which a metal layer (metallization layer) is allowed to be present between the base substrate and the lid, and the metal layer is heated and melted by laser irradiation to thereby bond them together (so-called laser sealing).
The laser sealing is an excellent method, compared to other methods, from the viewpoints of bonding accuracy, bonding strength, and the like, but cannot be applied to the piezoelectric element of Patent Document 1 having no metallization layer. Moreover, if a metallization layer is disposed, instead of the insulating layer and the insulating adhesive, in the electronic device of Patent Document 1 for applying the laser sealing, the metallization layer overlaps with and is connected to a lead terminal that connects a connection electrode (quartz crystal holding terminal) formed on an upper surface of the base substrate with a mounting terminal formed on a lower surface of the base substrate. Therefore, in laser sealing, heat applied to the metallization layer escapes to the outside of the metallization layer via the lead terminal. Therefore, variation in temperature is generated in the metallization layer, along with which variation in bonding strength between the lid and the base substrate is generated.